In existing IP networks, various mechanisms have been deployed over time to ensure a certain degree of load balancing. In particular, round-robin Domain Name Service (DNS) has generally been used to balance the load between servers belonging to the same domain for hosting content. However, this form of load balancing does not always lead to a consistently balanced load across servers. This may be attributed to the lack of consideration regarding the amount of resources required by data sessions as well as their expected duration. Accordingly, a host-based networking model can be inefficient for accessing multimedia data open to large populations of users dispersed throughout the Internet.
Information-oriented networks (IONs) perform fine-grained traffic engineering across network routes. IONs give IP routers an awareness of content in order to enable them to take a more active role in the routing and delivery of content. In turn, flexible traffic engineering policies can account for the requirements of Internet Service Providers (ISPs) and content consumers. However, a number of challenges related to traffic engineering still exist.
One challenge of IONs is their use of content names in lieu of IP addresses. The supporting ION protocols and mechanisms must be designed with scalability in mind. This can be challenging because the number of contents is significantly greater than the number of servers. Routing by content rather than location therefore can lead to unsustainable networks in the absence of proper scalability provisions.
Another challenge of IONs is attributed to its features of decoupling content identifiers from location information, e.g., IP addresses. Generally, consumers directly interact with the network to retrieve content they are interested in without requiring information on the exact location of the server or cache hosting the content. However, content routers are not made aware of the explicit location of content. Instead, they are only made aware of its implicit direction. This can pose challenges when disseminating information about server loads and path congestion within a domain, as this information can no longer be associated with explicit server IP addresses. Decoupling also makes it harder to relay context information related to content. This is due to the lack of semantic value in explicitly relating this context information to server identifiers.
A further challenge of IONs is localizing content dissemination. Content dissemination should generally be localized around the content consumer. However, this reduces the content retrieval latency for the user. This also reduces the amount of inter-domain traffic.